#region Copyright (c) 2006-2012 nHydrate.org, All Rights Reserved
// --------------------------------------------------------------------- *
//                           NHYDRATE.ORG                                *
//              Copyright (c) 2006-2012 All Rights reserved              *
//                                                                       *
//                                                                       *
// This file and its contents are protected by United States and         *
// International copyright laws.  Unauthorized reproduction and/or       *
// distribution of all or any portion of the code contained herein       *
// is strictly prohibited and will result in severe civil and criminal   *
// penalties.  Any violations of this copyright will be prosecuted       *
// to the fullest extent possible under law.                             *
//                                                                       *
// THE SOURCE CODE CONTAINED HEREIN AND IN RELATED FILES IS PROVIDED     *
// TO THE REGISTERED DEVELOPER FOR THE PURPOSES OF EDUCATION AND         *
// TROUBLESHOOTING. UNDER NO CIRCUMSTANCES MAY ANY PORTION OF THE SOURCE *
// CODE BE DISTRIBUTED, DISCLOSED OR OTHERWISE MADE AVAILABLE TO ANY     *
// THIRD PARTY WITHOUT THE EXPRESS WRITTEN CONSENT OF THE NHYDRATE GROUP *
//                                                                       *
// UNDER NO CIRCUMSTANCES MAY THE SOURCE CODE BE USED IN WHOLE OR IN     *
// PART, AS THE BASIS FOR CREATING A PRODUCT THAT PROVIDES THE SAME, OR  *
// SUBSTANTIALLY THE SAME, FUNCTIONALITY AS THIS PRODUCT                 *
//                                                                       *
// THE REGISTERED DEVELOPER ACKNOWLEDGES THAT THIS SOURCE CODE           *
// CONTAINS VALUABLE AND PROPRIETARY TRADE SECRETS OF NHYDRATE,          *
// THE REGISTERED DEVELOPER AGREES TO EXPEND EVERY EFFORT TO             *
// INSURE ITS CONFIDENTIALITY.                                           *
//                                                                       *
// THE END USER LICENSE AGREEMENT (EULA) ACCOMPANYING THE PRODUCT        *
// PERMITS THE REGISTERED DEVELOPER TO REDISTRIBUTE THE PRODUCT IN       *
// EXECUTABLE FORM ONLY IN SUPPORT OF APPLICATIONS WRITTEN USING         *
// THE PRODUCT.  IT DOES NOT PROVIDE ANY RIGHTS REGARDING THE            *
// SOURCE CODE CONTAINED HEREIN.                                         *
//                                                                       *
// THIS COPYRIGHT NOTICE MAY NOT BE REMOVED FROM THIS FILE.              *
// --------------------------------------------------------------------- *
#endregion
using System;
using System.Security.Cryptography;
using System.Text;

namespace nHydrate.Generator.Common.Util
{
	public class HashHelper
	{
		#region Private member variables...
		private string mSalt;
		private readonly HashAlgorithm mCryptoService;
		#endregion

		#region Public interfaces...

		public enum ServiceProviderEnum: int
		{
			SHA1, 
			SHA256, 
			SHA384, 
			SHA512, 
			MD5
		}

		public HashHelper()
		{
			mCryptoService = new SHA1Managed();
		}

		public HashHelper(ServiceProviderEnum serviceProvider)
		{ 
			// Select hash algorithm
			switch(serviceProvider)
			{
				case ServiceProviderEnum.MD5:
					mCryptoService = new MD5CryptoServiceProvider();
					break;
				case ServiceProviderEnum.SHA1:
					mCryptoService = new SHA1Managed();
					break;
				case ServiceProviderEnum.SHA256:
					mCryptoService = new SHA256Managed();
					break;
				case ServiceProviderEnum.SHA384:
					mCryptoService = new SHA384Managed();
					break;
				case ServiceProviderEnum.SHA512:
					mCryptoService = new SHA512Managed();
					break;
			}
		}

		public HashHelper(string serviceProviderName)
		{
			try
			{
				// Set Hash algorithm
				mCryptoService = (HashAlgorithm)CryptoConfig.CreateFromName(
					serviceProviderName.ToUpper());
			}
			catch
			{
				throw;
			}
		}

		public virtual string Encrypt(string plainText)
		{
			var cryptoByte =  mCryptoService.ComputeHash(
				ASCIIEncoding.ASCII.GetBytes(plainText + mSalt));
	 
			// Convert into base 64 to enable result to be used in Xml
			return Convert.ToBase64String(cryptoByte, 0, cryptoByte.Length);
		}

		public static string Hash(string plainText)
		{
			var mCryptoService = new SHA1Managed();
			var cryptoByte = mCryptoService.ComputeHash(ASCIIEncoding.ASCII.GetBytes(plainText));

			// Convert into base 64 to enable result to be used in Xml
			return Convert.ToBase64String(cryptoByte, 0, cryptoByte.Length);
		}

		public bool Match(string input, string hashValue)
		{
			return StringHelper.Match(this.Encrypt(input), hashValue, true);
		}

		public string Salt
		{
			// Salt value
			get { return mSalt; }
			set { mSalt = value; }
		}
		#endregion
	}
	
}
